import lpt.*;

public class Reader {

	public static void main(String[] args) {
		ErrorLpt henk = new ErrorLpt();
		int fouten = 0;
		for(int i = 0; i < 1000; i++) {
			byte a = henk.readLPT();
			int b = 0;
			switch (a) {
			case 0:
				b = 0;
				break;
			case 16:
				b = 2;
				break;
			case 32:
				b = 1;
				break;
			case 48:
				b = 3;
				break; 
			}
			if(b != 0) {
				fouten++;
				if(b == 3) {
					fouten++;
				}
			}
			try {
				Thread.sleep(100);
			} catch (InterruptedException e) {
				e.printStackTrace();
				System.exit(-1);
			}
		}
		double percentage = (fouten / 2000) * 100;
		System.out.println(percentage);
	}
}
